Bullet mold

ABSTRACT

A bullet mold is provided with two block-like halves which are formed as part of an extruded aluminum bar, cut off, and then reversed to form a complimentary matching pair. Mating V-grooves and raised ribs disposed along the longitudinal edges of the inner mold block faces provide ease of transverse location. Pin and groove means provide longitudinal location. Longitudinal air vents are disposed proximate the mating V-grooves and ribs, and the planular mating faces are knurled to provide fine vent grooves leading from the mold cavity to the longitudinal vents. The sprue plate is held in position by a wave washer to eliminate undesirable torque. The mold cavity is formed by rotating the clamped halves in a screw machine spindle and using appropriate tools.

United States Patent [1 1 Lee BULLET MOLD [76] Inventor: Richard J. Lee, R. R. 2, Hartford,

Wis.

[22] Filed: Aug. 3, 1971 [21] App]. No.: 168,569

1111] 3,745,873 51 July 17,1973

Primary Examiner-Benjamin A. Borchelt Assistant Examiner-Harold Tudor Attorney-Andrus, Sceales, Starlke & Sawall 57] ABSTRACT A bullet mold is provided with two block-like halves which are formed as part of an extruded aluminum bar, cut off, and then reversed to form a complimentary matching pair. Mating V-grooves and raised ribs disposed along the longitudinal edges of the inner mold block faces provide ease of transverse location. Pin and groove means provide longitudinal location. Longitudinal air vents are disposed proximate the mating V- grooves and ribs, and the planular mating faces are knurled to provide fine vent grooves leading from the mold cavity to the longitudinal vents. The sprue plate is held in position by a wave washer to eliminate undesirable torque. The mold cavity is formed by rotating the clamped halves in a screw machine spindle and using appropriate tools.

8 Claims, 14 Drawing Figures PATENTED JUL I 7 E73 sum 1 HF T3;

INVENTOR RICHARD .1. L

ATTORNEYS m5mr3 PATENTED JUL 1 7 i873 SHEH 2 0F 3 INVENTOR RICHARD J.LEE

ATTORNEY PATENTEB JUL 1 7 m5 sum 3 0F 3 TTORNEYS BULLET MOLD BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to a bullet mold and contemplates improved manufacture and structure for hand operated bullet molds which are formed in two halves and held tightly together during molding.

More specifically a bullet mold is provided with two block-like halves which are formed as part of an extruded aluminum bar, cut off, and then reversed to form a complimentary matching pair. Mating V- grooves and raised ribs disposed along the longitudinal edges of the inner mold block faces provide ease of transverse location. Pin and groove means provide longitudinal location. Longitudinal air vents are disposed proximate the mating V-grooves and ribs, and the planular mating faces are knurled to provide fine vent grooves leading from the mold cavity to the longitudinal vents. The sprue plate is held in position by a wave washer to eliminate undesirable torque. The mold cavity is formed by rotating the clamped halves in a screw machine spindle and using appropriate tools.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate the best mode presently contemplated by the inventor for carrying out the invention.

In the drawings:

FIG. I is a top plan view of a bullet mold constructed in accordancewith the invention, and with the mold blocks closed, and showing the positions of the sprue plate;

FIG. 2 is a view similar to FIG. I with the mold blocks open;

FIG. 3 is a bottom plan view of the bullet mold with the mold blocks closed;

FIG. 4 is a side elevation of the mold;

FIG. 5 is a plan view of the faces of the mold blocks placed in side by side relation;

FIG. 6 is a transverse section taken on line 6-6 of FIG. 5;

FIG. 7 is a longitudinal section taken on line 7-7 of FIG. 5 through the right hand block thereof;

FIG. 8 is a longitudinal section taken on line 8-8 of FIG. 5 through the left hand block thereof;

FIG. 9 is a longitudinal section taken on line 99 of FIG. 4 through the closed mold with the sprue plate in pouring position;

FIG. III is a schematic view showing the extruding, knurling and cut-off steps;

FIG. II is a schematic view showing compression of the pair of blocks;

FIG. I2 is a perspective schematic view showing clamping and drilling of the transverse hole;

FIG. I3 is a perspective schematic view showing finishing of the bullet cavity end; and

FIG. M is a sectional schematic view showing finishing of the bullet cavity walls.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1-4 of the drawings, the hand bullet mold of the invention comprises a Scissor-like clamping handle I pivoted as at 2 and having a pair of clamp arms 3. Arms 3 are adapted to centrally hold a pair of facing mold blocks 4, 5 for relative pivoting movement into and out of closed molding position. For this purpose, a transverse slot 6 having a curved concave base 7 is formed centrally in the outer wall of each block, with each slot fitting over the inner convexly curved edge 8 of the respective arm 3. A longitudinal screw 9 extends through each block I, 5 and through an opening I0 in the respective arm 3 to loosely mount the block in place. The parts are arranged so that curved base 7 and edge 8 are spaced slightly apart, thus permitting slight transverse pivotal movement of each block, with a stop provided by engagement of either end of slot base 7 with arm edge 3.

Referring to FIGS. 5-9, each mold block 4, 5 is provided with a centrally disposed pIanular inner face I I, a V-groove I2 along one longitudinal edge, and a raised generally V-shaped rib I3 along the opposite longitudinal edge. The apex of rib I3 may be blunted for clearance purposes. When the unit is assembled, blocks 4 and 5 are reversed in orientation so that closing of the mold causes pivoting of the blocks on screws 9 and causes rib I3 of each block to enter complimentary groove I2 of the opposed block until faces II matingly engage. See FIGS. I and 3. Grooves I2 and ribs I3 thus serve to properly locate the blocks transversely.

In addition, means are provided to properly locate the blocks in a longitudinal direction. For this purpose, an elongated locator pin I4 is press-fit into a transverse groove 15 disposed along one end of face II of block 4, with pin I4 adapted to enter a complimentary facing transverse groove I6 disposed similarly in block 5. Grooves 15 and I6 are formed, as will be further described, so that groove I5 is about twice as deep as groove I6, thus allowing the press fit.

The face of each block is provided with a longitudinal semi-circular bullet mold cavity portion I7, with portions I7 forming a suitable complete cavity I8 when the mold is closed. Cavity I3 opens outwardly from the mold at the opposite end from pin Id and is adapted to pouringly receive molten metal for the bullet. As cavity 18 is filled, provision must be made for the escape of air therefrom. For this purpose, fiaces II are provided with a grill-like plurality of fine closely spaced diagonally extending grooves I9. In addition, a shallow longitudinal venting groove 26 is disposed parallel to and proximate the base or root of each rib I3 adjacent face Ill, thus forming with the opposite face II a pair of open-ended venting channels 22 when the mold is closed. Grooves I9 are in communication with cavity I8 and channels 22 so that air is vented therethrough to the outside during metal pouring.

As shown in FIGS. 2 and 4, structure of the device also includes a flat sprue plate 23 having an opening or sprue 24 therein and which is pivotally mounted to the end of block 4 which contains the opening for cavity I8. For this purpose, a screw 25 passes through a bushing 26 in plate 23, and through an annular uninterrupted wave washer 27 into block I. Wave washer 27 is so named because it is provided with a series of undulations 28 which maintain tension between the screwhead bushing-head assembly and sprue plate 23 to hold the plate down without any torque applied to the plate. An edge of plate 23 includes a bent portion forming a stop 29, which engages the outer longitudinal wall of block 5 when sprue MI is aligned above cavity I8. The torque-less construction prevents stop 29 from backing off from block 5 and thus maintains the openings in alignment.

It has been found preferable to manufacture the mold from relatively soft aluminum, so that it is more easily formable then conventional cast iron, which is more porous and tends to hold minute amounts of oil therein which is difficult to vent. Break-in is therefore usually not needed with aluminum.

Referring to FIGS. -14, the bullet mold is made by extruding an aluminum bar 30 through any suitable well-known extrusion device 31, so that a continuous face 11, V-groove 12, rib 13 and vent groove 20 are already formed on one bar side. After extrusion, bar 30 is passed across a rotating diagonal knurl 32 which forms diagonal venting grooves 19 in face 11. A pair of blocks are then cut from bar 30, as by a cutter 33. The blocks are then reversed and placed face-to-face in a high compression press 34 to improve the fit thereof. In the process, the diagonal grooves 19 of each block leave an impression on the other block to form the grilllike appearance. The reversed blocks are subsequently clamped together in opposed relation, as by clamp 35. A drill 36 is then utilized to bore transversely into the clamped assembly to provide an elongated bore 37 which is parallel to but slightly offset from the plane 38 of mating faces 11. The offset is such that preferably two-thirds of the diameter of bore 37 is in block 4 and the remaining one-third is in block 5. When the blocks are. opened, bore 37 separates into grooves and 16, described previously. Bore 37 and the resultant groove 15 and pin 14 extend inwardly through rib l3 and groove in block 4, along face 11 and terminates proximate the inner edge of V-groove l2. Groove 16 in block 5 extends from V-groove 12 to proximate groove 20.

Subsequently, the clamped blocks 4, 5 are placed in a screw machine spindle 39 and rotated on the axis desired for the bullet cavity 18. See FIGS. 12 and 13. After rough drilling of the cavity by any suitable means, not shown, a finishing tool 40 forms the pointed bullet cavity end 41. Then, a cutting blade type recessing tool 42 is moved axially into the cavity and is then moved radially outwardly to form the finished cavity walls, including suitable ridges 43.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A bullet mold comprising:

a. a clamping device having a pair of facing relatively movable clamping members,

b. and a pair of complimentary opposed mold blocks loosely mounted to said clamping members and pivotable relative thereto and movable thereby into and out of closed mating position,

c. each of said mold blocks having a longitudinally extending bullet molding cavity portion which mates with the cavity portion of the other block when the mold is closed to form a complete molding cavity,

d. first cooperative locator means disposed on the inner facing portions of said pair of mold blocks for locating said pivotable blocks transversely when the mold is closed,

e. and second cooperative locator means disposed on the inner facing portions of said pair of mold blocks for locating said pivotable blocks longitudinally when the mold is closed.

2. The bullet mold of claim ll wherein said first locatOl' means comprises:

a. a groove disposed along one longitudinal edge of the inner face of each said mold block,

b. and a raised rib disposed along the other longitudinal edge of the inner face of each said mold block,

c. the rib on each block being disposed opposite the groove of the other block so that the respective ribs and grooves complimentingly mate when the mold is closed.

3. The bullet mold of claim 1 wherein said second locator means comprises:

a. a transverse groove extending across the inner face of each said mold block, with said grooves in facing positions,

b. and a locator pin disposed in one of said grooves and adapted to enter the other of said grooves when the mold is closed.

4. The bullet mold of claim 3 wherein:

a. the groove within which said pin is located is deeper than the other of said grooves,

b. and said pin is press-fit into its respective groove.

5. The bullet mold of claim 2 which includes: vent means for providing escape of air from said cavity as it is filled with molten metal.

6. The bullet mold of claim 5 wherein the inner facing portions of each said mold block are provided with matable generally planular faces, and wherein said air vent means comprises:

a. a plurality of closely spaced diagonally extending grooves disposed in said faces and communicating with said cavity,

b. and a longitudinal venting groove extending parallel to and proximate the root of each said raised rib and communicating with said diagonal extending grooves,

c. said venting grooves forming with the respective opposite block faces a pair of open-ended air venting channels when the mold is closed.

7. A bullet mold comprising:

a. a clamping device having a pair of facing relatively movable clamping members,

b. and a pair of complimentary opposed mold blocks loosely mounted to said clamping members and pivotable relative thereto and movable thereby into and out of closed mating position,

0. each of said mold blocks having a longitudinally extending bullet molding cavity portion which mates with the cavity portion of the other block when the mold is closed to form a complete molding cavity,

d. cooperative locator means disposed on the inner facing portions of said pair of pivotable mold blocks for locating said blocks transversely and longitudinally when the mold is closed,

e. a sprue plate disposed at the end of one of said blocks and having a sprue movable into alignment with said cavity,

f. and torque-less means for mounting said sprue plate on the said one of said blocks.

8. The mold of claim 7 wherein said torque-less means comprises:

a. a screw extending through said sprue plate into the 7 end of the said one of said blocks, b. and an annular uninterrupted undulating wave washer disposed between the head of said screw and said sprue plate. 

1. A bullet mold comprising: a. a clamping device having a pair of facing relatively movable clamping members, b. and a pair of complimentary opposed mold blocks loosely mounted to said clamping members and pivotable relative thereto and movable thereby into and out of closed mating position, c. each of said mold blocks having a longitudinally extending bullet molding cavity portion which mates with the cavity portion of the other block when the mold is closed to form a complete molding cavity, d. first cooperative locator means disposed on the inner facing portions of said pair of mold blocks for locating said pivotable blocks transversely when the mold is closed, e. and second cooperative locator means disposed on the inner facing portions of said pair of mold blocks for locating said pivotable blocks longitudinally when the mold is closed.
 2. The bullet mold of claim 1 wherein said first locator means comprises: a. a groove disposed along one longitudinal edge of the inner face of each said mold block, b. and a raised rib disposed along the other longitudinal edge of the inner face of each said mold block, c. the rib on each block being disposed opposite the groove of the other block so that the respective ribs and grooves complimentingly mate when the mold is closed.
 3. The bullet mold of claim 1 wherein said second locator means comprises: a. a transverse groove extending across the inner face of each said mold block, with said grooves in facing positions, b. and a locator pin disposed in one of said grooves and adapted to enter the other of said grooves when the mold is closed.
 4. The bullet mold of claim 3 wherein: a. the groove within which said pin is located is deeper than the other of said grooves, b. and said pin is press-fit into its respective groove.
 5. The bullet mold of claim 2 which includes: vent means for providing escape of air from said cavity as it is filled with molten metal.
 6. The bullet mold of claim 5 wherein the inner facing portions of each said mold block are provided with matable generally planular faces, and wherein said air vent means comprises: a. a plurality of closely spaced diagonally extending grooves disposed in said faces and communicating with said cavity, b. and a longitudinal venting groove extending parallel to and proximate the root of each said raised rib and communicating with said diagonal extending grooves, c. said venting grooves forming with the respective opposite block faces a pair of open-ended air venting channels when the mold is closed.
 7. A bullet mold comprising: a. a clamping device having a pair of facing relatively movable clamping members, b. and a pair of complimentary opposed mold blocks loosely mounted to said clamping members and pivotable relative thereto and movable thereby into and out of closed mating position, c. each of said mold blocks having a longitudinally extending bullet molding cavity portion which mates with the cavity portion of the other block when the mold is closed to form a complete molding cavity, d. cooperative locator means disposed on the inner facing portions of said pair of pivotable mold blocks for locating said blocks transversely and longitudinally when the mold is closed, e. a sprue plate disposed at the end of one of said blocks and having a sprue movable into alignment with said cavity, f. and torque-less means for mounting said sprue plate on the said one of said blocks.
 8. The mold of claim 7 wherein said torque-less means comprises: a. a screw extending through said sprue plate into the end of the said one of said blocks, b. and an annular uninterrupted undulating wave washer disposed between the head of said screw and said sprue plate. 